Rotary machine having a fluidworking medium



June 15, 1965 G. E. BJORKLUND 3,

ROTARY MACHINE HAVING A FLUID-WORKING MEDIUM Filed March 14,-1965 3 Sheets-Sheet 1 June 15, 1965 G. E. BJCSRKLUND 3,183,918

ROTARY MACHINE HAVING A FLUID-WORKING MEDIUM Filed March 14, 1963 s Sheets-Sheet 2 Fig.3

Avrzwme June 15, 1965 G. E. BJORKLUND 3,188,918

ROTARY MACHINE HAVING A FLUID-WORKING MEDIUM Filed March 14, 1965 3 Sheets-Sheet 3 United States Patent 2 Claims. or. 911-204 This invention relates to rotary machines of the type comprising a centrally arranged pintle acting as a valve, a rotor mounted on the pintle and provided with cylinder spaces each of which has a port which cooperates with the pintle and during rotation of the rotor on the pintle is successively connected to and disconnected from an inlet duct and an outlet duct in the pintle, and a ring mounted eccentrically to the pintle said ring surrounding the rotor and engaging pistons which are movable in the cylinder spaces and during rotation of the rotor are propelling the ring and at the same time are reciprocated thereby between two dead centre positions. In particular, the invention relates to a construction of the type in which the machine acts as a motor and the working medium of which is a compressed gaseous medium, such as cornp-ressed air. In order to have the machine operated in the most favourable manner, the cylinder spaces must be put into communication with the inlet and outlet in exact accurate position of the pistons during the cycle of operation. This position varies with the pressure, speed and piston stroke if said stroke is variable. It may also be advantageous to interrupt the communication between the cylinders and the ducts during part of the cycle of operation, the gas enclosed in the cylinder spaces expanding or being compressed during said part. By selecting suitable opening angles of the pintle it is easily possible in this manner to obtain an optimum operation of the motor for given conditions. However, there are often different stipulations requiring change of the operation of the motor, for instance increase or decrease of the torque or reversal of the direction of rotation. Such changes are suitably obtained by varying the eccentricity of the ring relative to the pintle which means that the axis of rotation of the rotor has to be displaced relative to the axis of the surrounding ring. A simple, inexpensive and practical manner to realize this fact consists in a translational displacement of the pintle. The object of the present invention is to provide a device which renders possible displacement of the pintle in a manner such as to maintain favourable datum angles of the pintle at varying eccentricity and clockwise as well as counter-clockwise rotation.

In the broadest aspect of the invention the pintle is guided relative to the ring by means which render possible translational displacement of the pintle While maintaining a certain angular displacement of the pintle-datum angle'relative to the angular position of the rotor in which the iston changes its direction of motion, with or Withoutchange of said datum angles during displacement. The datum angle may be selected such that a precompression is obtained and that the pressure due to said precompression in the cylinder space inside the piston is equal to the pressure which prevails in the inlet duct of the pintle when the port is opening into said cylinder space. If in case of equidistantly located cylinders in the rotor the distances between the ports and the cylinders are equal and the ports are suitably spaced apart, favourable condition of admission similar in character will be obtained in all cylinders resulting in the highest average pressure possible in the motor as well as the highest torque possible.

3,188,918 Patented June 15, 1965 Suitable adjustment of the above named datum angle is dependenton the working pressure in the inlet of the motor the speed of the rotor and the stroke of the pistons. There exists one setting only which suits a given condition of operation and a given direction of rotation. On reversing the direction of rotation the datum angle has to be changed if the same conditions are to be obtained as in the case of the original direction of rotation-and with other factors remaining constant. This is a difiicult operation if the pintle first has to be adjusted with respect to the eccentricity and thereupon has to be turned. In accordance with an important development of the inventive idea the direction of rotation can be reversed in a very simple manner solely by a rectilinear displacement of the pintle relative to the casing of the motor in which the eccentric ring is journalled.

The invention is explained more closely with reference to the drawing in which FIG. 1 is a diagrammatic sectional view taken parallel to the'axis of a motor constructed in accordance with the invention. And FIG. 2 shows the pintle in a similar section and a diagram illustrating the conditions on reversal of the direction of rotation. FIGS. 3 and 6 are diagrammatic radial sectional views and FIGS. 4, 4a and 5 are diagrams.

Referring to the drawing numeral 1 denotes a pintle and numeral 2 a rotor mounted for rotation on the pintle and having cylinder spaces 3 for pistons 4 which are radially movable in the cylinder spaces relative to the axis of rotation 0 of the rotor, six pistons being provided in the form of balls. The halls are in contact with recesses 5 of a roll race formed on the internal side of surrounding ring 6 which like the rotor 2 is mounted in the frame or casing (not shown) of the motor so as to he rotatable about an axis 0' which is located eccentrically with respect to the pintle 1. The pintle has longitudinally extending recesses forming an inlet duct 7 for a compressed gaseous medium, preferably compressed air and an outlet I duct 8 for discharged working medium. During rotation of the rotor the ring 6 is propelled by the balls 4 which engage the recesses 5 on the internal side of the ring and act both as pistons and as locking members. Due to the eccentricity of the ring 6 relative to the pintle and the rotor the balls will move during each revolution from an inner dead centre assumed by the ball 4a outwards in the cylinder space to an outer dead centre position as assumed by the ball 4b. The cylinder spaces communicate with ports 9. During one revolution each port passes successively the inlet duct 7, a pintle surface 10, the outlet duct 8 and a pintle surface 11. The stroke of the pistons equals twice the eccentricity which is the distance between 0 and 0'.

The recesses in the pintle 1 which form the inlet duct 7 and the outlet duct 8 are bounded by plane parallel surfaces 12 and 14, located at different distances from the axis of rotation 0 such that the cross-sectional area of the inlet duct 7 is smaller than that of the outlet duct 8.

tion indicated by the arrow RB. v A plane of symmetry ofthe pintle at a right angle to the plane surfaces 12, 14 thereof is indicated by a chain-dotted line 15. The angular position in which the piston is at its inner dead centre is indicated at VA for the direction of rotation RA and at VB for the direction of rotation RB. In the position 9a the port is about to be connected to the inlet 7, and in the -position'9 b the port has just been "covered. The angle between these positions, that is, theinlet angle is indicated at a. In' the position 9c the port is about to be connected to the outlet 8 and in the position 9d it has just been covered. The angle between these a single straight line. ,If it is desired to maintain the 1 datum angle constantfor difierent values of the eccenpositions, that is, the outlet angle is. equal to oc+2l+2v wherein 8 is the angle through which the centre of the port moves from the inner dead centre positionVA to the position in which the port is aboutto be connected'tothe inlet, and 'y is the angle through which the centre of the port moves ncm the'm'ornent when the communication with the outlet'duct 'Sis' about to be openedtofthe outer 7 dead centre po's'ition (which i the position'of the m t in which the, corresponding; piston assumes its corresponding dead centre position). [3 is the" angular distance" during which compression and expansion, respectively, of the working medium takes'place in the cylinder space. 4 It will be seen from FIG; 2 that if ,rotor is driven clockwise the pintle is positioned atan angle equal to" degr ee'sffrom the direction of rotation as measured from v V tricity- Ethe device. isconstructed as principally shown 7' in F163. 4 ,and 4a. FIG. 4 illustrates'a pintle diagram similar to thatshown inFIG Z, and from FIG. 4a: it is to be seen that the ring'is not displaced directly from A to B, but rectilinearly from; A1t0 o and thereupon rectilinearly from o to' B; It canbe. seen directly from FIGS; 4' and 4a thatthe datum angle remains unchanged during displacement whereas E; is varying. When the center of rotation of the' cylinders is displaced from A to o to B the eccentricityprogresses from positive maxi- V mum to zero to negative maximum.

FIGS illustrates in a diagrammatic way displacement from A to B along a curved linewhich is symmetrical with respect to a Hueyy. In case of such a displacement the angles [3' and were decreased with decreasing E, whereas'e is increased. v

For practical performing of the displacement according'to'FiG. 5. asconstru'ction schematically shown in FIG. 6 may be used 'As comparedwithFIG. 3 the straight bores 19 for thepins 18 are replaced by curved races 21 for guide rollers:22 which are rotatablymounted the inner deadcentr'el position VA. The same "angle startinglfr'oni the-position VB is obtainedincase of counter-clockwise rotation. 'smeein this case the inlet 7 is located oaths same side ofthepintle, a; e and: I

ocH 2fl+25 willbe the same for both directions ofrota-fl tion which meansthat all of'the characteristic angles will be unchanged irrespective of the direction of rotation.

V Numeral 24 denotes the curved line,

on radialarms 23 oftherbearing 16' for the pintle 1. 7 along which the centre 0 of the pintleismoved. i w As will appear from the above, the present invention opens the possibility of selecting optimum and equal conditions forboth directions of rotation which is very im- In FIGURE 2 the datuinangle'fis defined. by the intersec- 7 'tion of a line through tlie'center of rotation 0 of the row tor andfthe center of rotation A of the cylinders and a li'ne through 0 and through the axis of the cylinder at 9a where the cylinde'ris about to be uncovered at the inlet. .Thus, the datum angle is shown at 5.

Usually the ring 6 is rotatably but non-displaceably mounted in the casing of the motor whereas the pintle and the rotor are'tr ansversely displaceable in'the casing for varying the eccentricity and consequently the stroke of the pistons' Asvwill be apparent from FIGQZ re:

versal of the direction of rotation is obtained by displao ing the rotor and thepintlejrelative tothe rin'grsuchthat the axis of. rotation ofthe ring coincides with the point I B instead of the 'point'Aorvice versa. 7 Consequently, the

most simple way of reversing themotor is to move the rotor and pintle parallel to the line AB whichinthe.

"portan't for instance in case of high speed motors for the purpose in consideration where the motor is required tobe able to' run in both directions of-rotation without changes of performance. It is not possible to i 1. In a rotary machine embodiment illustrated isparallel' tothe plane surfaces 12 and 14, which boundthe -inlet and outlet ducts. For maximum piston stroke the eccentricity E zE zE which means that the eccentricity in the position A is! equal to the eccentricity in the positionB. The'perpen dincular distance between the axis .0 ofrotation ofthe rotor and the line AB is denoted at e, which distance may be considered the eccentricity of the ring at right angles to the-surfaces 12 and 1450f the pintle. between e" and E equation"- ;iEiasgn) j A characteristic Way of rendering possible rectilinear displacementis shown-'in FIG. 3 in which numeral '16 denotes a bearing forthepintle 1 and numeral 18 denotesa pair of radiali'pinswhich are connected to thebearing and by means; of which the bearing can be dis v placed relative to the, motor casing 17. i The bearing has I The relation according to FIG. 2 is given by the obtain top speeds of the order of 75,000 rpm. or more without attending-to the described'optir'num regarding the datum angle. For this reason the-inventiony described is highly: advantageous if it is desired to reverse the direction of rotation in a simple manner while maintaining predetermined performanceidata constant.

The above described arrangements are examples only ofthe invention. While the'ipintle illustrated has plane f boundary surfaces 12, 14; at the inlet and outlet ducts, other shapes mayjbe" used andinay bemore suitable in certain cases. p

.What is claimedisiq' W I u I having a fluid working medium, a pintle having opposite surfaces defining inlet and out- 7 let openings/for said medium, a rotor rotatably' mounted on the pintlefand i having cylinder spaces and ports, a said port communicating with each of said cylinder spaces,jtheppintle' comprising a valve to connect and disconnect said inlet andoutlet openings with the cylinder spaces successively by way? of said; ports during rotation-ojf the'rotor on the pintle, a ring encompassing the rotor, pistons mounted in the cylinder spaces for reciprocation radially therein, the ring retaining the pistons in'said piston spaces, means for mounting the rotor and the ring so that their centers are spaced apart in one direction, and means for moving the axes'of the rotor and the ring'relative to each other between first and second positions such that the axes .of the rotor and'the ring in 7 said first position lie in a'first plane and the axes of'the rotor and the'riug in said. secondposition lie in' a second plane and said'first and second planes. are disposed .at a'substantial' angle to each other.

2. A machine as. claimed in claim 1, said opposite surfaces oflsaid' pintle'having end'edges adjacent said 7 V rotor, the end edges of one of said surfaces being dis- .posedin a third plane parallel to saidaxes, the end edges of theother of said surfacesbeing disposed in a further plane'parallel to said axes, said thir'dyand fourth planes being'parallel toeach other, and said first and second planesforming equal andopposite angles with said third and fourth planes in; said first and second positions.

(References on following page) I References Cited by the Examiner UNITED STATES PATENTS Houtzenroeder 103161 Adams 103-461 Horton 103-161 Horton 103-161 Buchanan 103--161 Prshansky 103161 Nallinger et a1 103161 Bjorklund et a1 103-161 FRED E. ENGELTHALER, Primary Examiner. SAMUEL LEVINE, Examiner. 

1. IN A ROTARY MACHINE HAVING A FLUID-WORKING MEDIUM, A PINTLE HAVING OPPOSITE SURFACES DEFINING INLET AND OUTLET OPENINGS FOR SAID MEDIUM, A ROTOR ROTATABLY MOUNTED ON THE PINTLE AND HAVING CYLINDER SPACES AND PORTS, A SAID PORT COMMUNICATING WITH EACH OF SAID CYLINDER SPACED THE PINTLE COMPRISING A VALVE OF CONNECT SAID DISCONNECT SAID INLET AND OUTLET OPENINGS WITH THE CYLINDER SPACES SUCCESSIVELY BY WAY OF SAID PORTS DURING ROTATION OF THE ROTOR ON THE PINTLE, A RING ENCOMPASSING THE ROTOR, PISTONS MOUNTED IN THE CYLINDER SPACES FOR RECIPROCATION RADIALLY THEREIN, THE RING RETAINING THE PISTONS IN SAID PISTON SPACES, MEANS FOR MOUNTING THE ROTOR AND THE RING SO THAT THEIR CENTERS ARE SPACED APART IN ONE DIRECTION, AND MEANS FOR MOVING THE AXES OF THE ROTOR AND THE RING RELATIVE TO EACH OTHER BETWEEN FIRST AND SECOND POSITIONS SUCH THA THE AXES OF THE ROTOR AND THE RING IN SAID FIRST POSITION LIE IN A FIRST PLANE AND THE AXES OF THE ROTOR AND THE RING IN SAID SECOND POSITION LIN IN A SECOND PLANE AND SAID FIRST AND SECOND PLANES ARE DISPOSED AT A SUBSTANTIAL ANGLE TO EACH OTHER. 